Flame resistant fabric material



- February 1939, for duck, cotton,

Patented Scpb23, 1947 OFFICE 2,421,991 FLAME RESISTANT Fannie MATERIALClarence B. White, Montclair, N. J.

Serial No. 8 Claims. '(Cl. 117-437) This invention relates, generally,to improvements in the art of imparting fire resistance to cellulosicfibers and fabrics, as well as other relatively inflammable fibers andfabrics, while si-, -mu1taneously rendering the fibers and fabrics thusprotiessed, resistant to the action of weathering and attack by bacteriaand fungoid agencies, usually described under the collective title ofmildew, and the invention relates, more particularly, to product, and tothe process of preparing the same and the material with which theprocessing is effected. This application is a continuation-in-part of apSerial No. 457,- 226, filed September 3, 1942, for Flameproofing oftextiles and method of making the same.

The material to be treated of most common occurrence and commercialimportance is cotton duck, cotton sheeting, cotton camouflage and othertypes of netting, and the various types of cotton clothing fabric suchas drills and twills and poplins. At present commercially acceptablegrades of fire resistance must meet the requirements of Federalspecification CCC-D MG, fire, water and as amended by sup- (tentative)2fl2. Procweather resistance, and plementary specification essedmaterial the requirements of the above specified specifications may beconsidered as "fireproofed within the meaning of this invention.

Material processed as fireproof.which will meet the requirements ofspecifications 746 and 242, noted above, has hitherto beenprepared bythe application of a fire resistant paint formula in which groundpigments of various types are suspended in a halogenated organicmaterial which serves as a base and as a carrier for the essentialpigments. These pigment solids are preferably mixed or ground with thehalogenated carrier material (almost universally a chlorinatedcompound), and then deposited in and on the fabric, the chlorinatedmaterial serving as a, base or carrier, usually known as a vehicle.

fire resistance produced by the appaint meets the of the aforesaidspecifications, a very heavy is an indispensable prerequisite, the heavyloading producing the defect of tackiness at normal temperatures andobjectionable stiffness when subiected to the usual winter temperatureof the temperate zone, which stiffness is accentuated greatly whensubiected to arctic temperatures.

No Drawing. Application January 7, 1944,

While the degree of stiffness may be materially modified by the additionof relatively large amounts of plasticizing media. the addition ofplasticizing media greatly increases the degree of tackiness. Anotherobjection, vital in many cases, lies in of the soft fire resistant paintto croc off, selling any article with which come in contact, a defectwhich renders fabrics processed with such fire resistant paintsunavailable for clothing,

, chair or seat covers, and affects adversely their that willsubstantially comply with usefulness for tentage and awning purposes,largely for the reason that they will soil any fabric which comes incontact with them, and

having a soft tacky surface such processed fabrics attract dirt andgrime and quickly become unsightly, although still retaining their fireresisting characteristics.

The present invention does not make use of a fire resisting paintcomposition, but instead employs materials that are introduced into thefabric, fiber or structure to be fire proofed in the form of solutions,which are then insolubilized on and within the fibers of the cellulcsicstructure. These materials may be introduced into the fabric either inthe form of aqueous solutions of the salts of the metals and compoundsto be employed, or, where feasible in solutions of the desired compoundsin aliphatic, aromatic or chlorinated hydrocarbons, the hydrocarbon inthis latter case being first removed by evaporation, and the residualmetallic compound being then insolubilized (as to water) by means ofappropriate precipitants, usually compounds of the alkali metals. orammonia, such as the carbonates and hydroxides of the alkali metals.

The principal object of the present invention is to provide a novel fireresistant textile fabric material with the use of a minimum amount ofloading, 1. e., reducing the effective loading from 40 to percent ofloading ordinarily required in the case of fire reslstant texle fabricheretofore known.

Another object of the present invention is to provide a novelfireresistant textile fabric or similar material which will not crocknor will the fire resistant material rub off as in the case ofpaint-coated fabrics heretofore commonly used, whereby the material ofthis invention is adaptable for use for clothing, awnings, furniture,etc.

Another object of the present invention is to provide a novel fireresistant textile fabric or similar material that is not tacky and isfurther not stiff at low temperatures but possesses a de- 3 e 4- gree offlexibility approximating that of the uncarbonate and antimony chloride,is next passed treated fabric. through a solution of sodium carbonate,prefer- A still further object of the present invention ably warm, whichsolution immediately decomis to provide a flame resistant fabricprsimilar poses the'impregnated antimony chloride with material preferablyemploying antimony trioxide 5 the formation of antimony oxide.

\ V the, antimony group, antimony, bismuth and inhibitingcharacteristics. Because of the cost as the flame resistant ingredientthereof and also 1 The compounds of the antimony group [anti- It haslong been known that the chlorides of the chlorides of these metals,show marked flame of the group that can be considered of commercial may.therefore. be selected as a commercially importance. The chemicalcharacteristics of practicable type. but representative oiflthe men'- ois an invariable constituent of all cellulosic strucwere possible toimpregnate a cellulosic cent of the entire fabric and element antimony,antimony chloride is quite e soluble in alcohol and most hydrocarbonsolvents,

ric can be impregnated with a solution of anti- 4o Anfl'monymcmmde m thewhich. m tum, at once destroys the fabric. evolution of carbon dioxide,as follows:

Applicant has discovered that if the fabric 2SbCla+3Na=CO:-Sb:0a+6NaCl-l-3CO:

is first impregnated with a carbonate or acetate Antimony trioxide isinert insofar as the fabric or other weak salt of a metal of thealkaliou be emcemedsuch impregnating compound while. g; If the fabric destinedto be impregnated with mprgnate the fabric thus prepared with a s1u thenbe safely impregnated with an organic soludon of antimony m m ahydrocarboh sob tion of antimony trichloride. Under theseconre resistantpossesses an impregnation of carsodium chloride n c n dioxide.

solution of antimony trichloride addition to carbon dioxide.

ing, nothing remains but of the solvents.

carbonate solution (aqueous) or other equivalent carbonate. Second,

Third, the

the fabric is dried. (Usually on cans.) dried fabric is impregnated witha in an organic solvent.

' Fourth, the fabric impregnated with antimony trichloride is solventbeing volatilized.

" Fifth,

dried, the organic the dried fabric impregnated with antimonytrichloride is now passed through a warm sodium carbonate, whichsolution in dissolving the sodium carbonate already incorporated withthe fabric (first step), decomposes present as a result of the third andfourth steps, forming insoluble antimony trioxide, sodium chloride andsolution of Sixth, the thus processed fabric is now washed with water,which treatment removes the residual sodium carbonate, sodium chloride,and after drya fabric impregnated with antimony oxide which is now flameproofed. The fabric will not now support flame, but combustion can stillbe propagated through the fabric, but without flame effect.

The following will serve as an example of a working process.

First, the fabric or cellulosicstructure to be fireproofed is padded(that is, passed through a dye bath and squeezed through rollersor-nips") with a, hot carbonate (or equivalent carbonate) temperaturenear boiling, sodium carbonate being per cent of the whole.

Second, the fabric is dried on cans.

LThird, the dried, thus processed fabric is impregnated with a per centsolution of antimony chloride in an organic solvent, which may be a.petroleum or coal tar solvent or alcohol.

Fourth, the antimony impregnated fabric is dried on cans.

Fifth, the dried fabric (fourth step) is padded with a 10 per centsolution of sodium carbonate, warm but not hot.

Sixth, the processed fabric is washed and dried.

The processed fabric has now been flameproofed, but the treatment hereinproposed does not prevent the propagation of nameless comthe applicationThus, the fabric will glow, and the zone of combustion will creep,although actual flaming is no prevention of glowing" or the propagationof a creeping area of flameless combustion requires an additionaltreatment.

Certain organic compounds, principal among which may be namedchlorinated paraffin, tricresyl phosphate, tri-phenyl phosphate,polymers of vinyl resiri and various phenolic compounds will prevent thepropagation of a zone of creeping combustion but will not, inthemselves, prevent flame propagation. A combination of the two mediawill result in the production of a flreproofed fabric which will notonly not support flame propagation but creeping or glowing propagationof a zone of combustion as well.

These compounds may be added to the fabric processed as above by meansof a separate and distinct operation, or they may be incorporated withthe solution of antimony chloride in organic In the former case thefabric, processed as above described, is passed through a solution ofchlorinated paraffin, tricresyl phosphate, triphenyl phosphate,separately or a combination of after which the solvent may be removed byevaporation. On the other hand, the simultaneous application of theflame and "glow" inhibiting compounds would be effected as follows:

First, the fabric is incorporated wit a carbonate of the alkali metals.

Second, the fabric is dried.

Third, the dried fabric is impregnated with a solution of antimonytrichloride (15%) and chlorinated paraflin (20%) with cresyl phosphate(6%) in an aromatic or aliphatic hydrocarbon solvent, the usualproportion of this solvent being 50 per cent of the whole mixture,although this proportion is susceptible of variation'according tocircumstances,

Fourth, the fabric is now dried with the'evaporation of the solvent asan incident. The dried fabric will now contain the sodium carbonatebase, antimony chloride and the glow resistant hydrocarbon compounds,such as chlorinated paraffln, tricresyl phosphate, or whatever media mayhave been selected.

Fifth, the dried fabric now containing carbonate of soda (base),antimony chloride, glow resisting hydrocarbon compounds is now passedthrough a warm, though preferably not hot, 10 per cent solution ofsodium carbonate, squeezed through rolls and washed and dried over cans,or other methods of drying. This procedure has the effect of removingall carbonate of soda while converting the antimony chloride intoantimony oxide, while the glow inhibiting hydrocarbons are not changed.

What is claimed is:

1. The method of producing a fire resistant textile fabric comprisingimpregnating a fabric with sodium carbonate solution, drying the fabric,impregn'ating the dried fabric with a solution of antimony trichloridein an organic solvent, the presence of residual sodium carbonate in thefabric preventing any hydrochloric acid resulting from hydrolysis of theantimony trichloride from attacking the fabric, drying the thusimpregnated fabric, passing the fabric through a warm solution of sodiumcarbonate thereby precipitating insoluble antimony trioxide throughoutthe interstices of the fabric, washing the fabric with water to removeresidual sodium carbonate, drying the fabric, thereafter passing thefabric through a solution of chlorinated paramn and then again dryingthe fabric.

2. The method of producing a fire resistant textile fabric comprisingimpregnating the fabric with a of an alkali metal, drying the fabric,impregnating the dried fabric with a solution of antimony trichlorideand chlorinated paraffin in an organic solvent, drying the fabric, andpassing the same through a warm solution of sodium carbonate, squeezing,washing, and drying the fabric.

3. The method of producing a fire resistant fabric material comprisingimpregnating the material with an aqueous solution of an alkali metalcarbonate, drying the material, impregnating the dried material with anorganic solution of antimony trichloride, the presence of residualsodium carbonate in the fabric preventing any hydrochloric acidresulting from turdrolysis of the antimony trichloride from attackingthe fabric, again drying the material, passing the dried materialthrough an aqueous solution of an alkali carbonate, washing the materialto remove residual alkali carbonate, drying the material and passing thesame through a solution of chlorione or more of these ingredients, natedparaifin capable of rendering the fabric the inclusion of tri-'resistant to creeping combustion and again drying the fabric. 1

4. The method of producing a fire resistant textile fabric comprisingimpregnating the fabric with a carbonate of an alkali metal, drying thefabric, impregnating the dried fabric with a solution of anti fabric,impregnating the dried fabric with a solution of antimony trichloride inan organic solparaflin subsequent with sodium carbonate.

8. The method of producing a fire resistant textile fabric comprisingimpregnating the fabric 7. The method of fabric comprising passingsodium carbonate of approximate- 1y 10% concentration, drying thefabric, im-

eth

Number American 32, No. 14. p

and again drying the fabric.

0d of employing antimony trichloride same.

-CLARENCE B.- Wm I REFERENCES CITED The following references are file ofthis patent:

UNITED STATES PATENTS of record in the Name Date Arent Aug. 23, 1921McCuiioch June 16, 1936 Clayton Oct. 20, 1942 Dreyfus Apr. 7, 1936 OTHERREFERENCES Dyestuffs Reporter, ages 297 to 301.

July 5, 1943, vol.

